1. Field of the Invention
The present disclosure herein relates to near field communication (NFC) and, more particularly, to a receiving system for use in NFC and a mode detection method therefore.
2. Description of the Related Art
When a data transmitting device and a data receiving device are mutually disposed within a near field distance ranging from tens of centimeters to several meters, near field communication (NFC) is performed. For example, for contactless electronic payment or information recognition, a multimedia device such as a mobile phone is capable of communicating with a reader.
In an NFC system, transmitting data is transmitted through a transmission channel after being source-encoded in a predetermined encoding manner. For example, an initiator of ISO 18092 transmits a Manchester-encoded signal to an NFC target.
At the initial stage of transmission, the NFC initiator may transmit data in communication frame patterns of TYPEA 106 kbps, TYPEB 106 kbps, TYPEF 212 kbps (FELICA 212 kbps), and TYPEF 424 kbps (FELICA 424 kbps). Thus, what is required for allowing an NFC target to receive data is first to detect which protocol is the communication frame pattern, among NFC protocols. However, because data is not transmitted after any one communication mode among various types of protocols is preset at a target, an NFC target needs a device which is capable of detecting and receiving all communication modes of the various types of protocols.
A typical method for detecting an NFC communication mode is used to determine which protocol includes a communication frame pattern of data. According to the typical method, all devices capable of receiving protocols of TYPEA 106, TYPEB 106, FELICA 212, and FELICA 424 are provided in an NFC target and the TYPEA 106, the TYPEB 106, the FELICA 212, and the FELICA 424 are periodically set one after another by a control processor such as a central processing unit (CPU). Thus, if it is determined that data is normally received when a certain mode is set, a communication mode is decided as the set mode. However, the typical method requires relatively long time for detecting a communication mode and a complex procedure with software, which causes performance of a receiving device to be degraded.
Accordingly, there is a need for a receiving technique for use in near field communication (NFC) which is capable of rapidly detecting a communication mode and receiving data in the NFC.